CN213726794U - Primary air ring device of medium-speed vertical coal mill - Google Patents

Abstract

The utility model discloses a primary air ring device of a medium-speed vertical coal mill, belonging to the technical field of coal dust processing and comprising an inner ring and an outer ring; the inner ring and the outer ring adopt a split connection mode; the outer ring is fixed in the base shell of the coal mill, and the inner ring is fixed on a transmission yoke of the coal mill; the inner ring rotates along with the rotation of the coal mill transmission yoke; a folding seal multi-flow passage is arranged between the inner ring and the outer ring; a first wind resistance ring is arranged at the lower part in the shell of the coal mill base; the lower part of the inner ring is provided with a second wind resistance ring; the first wind resistance ring and the second wind resistance ring form a folding structure; the first choke ring, the second choke ring and the outer ring form a first chamber; the lower part of the outer ring is provided with a third choke ring, and the third choke ring and the outer ring body form a second chamber. The utility model discloses the primary wind flow that the inner ring blew out is to the law controllable, and the amount of wind is even, and a wind energy utilization rate is high, and the effective output rate of the amount of wind is high, to the quick vertical coal pulverizer productivity of centering, provide powerful help exerting oneself.

Description

Primary air ring device of medium-speed vertical coal mill

Technical Field

The utility model relates to a buggy processing technology field, in particular to vertical coal pulverizer of intermediate speed wind ring device.

Background

The medium-speed vertical coal mill is mostly applied to a power plant pulverizing system, and a primary air ring device of the medium-speed vertical coal mill is an important component of the coal mill. The medium speed vertical coal mill is usually used to grind coal into coal powder by means of impact, extrusion or rolling, and its grinding part is composed of rotary driving yoke and three fixed and rotatable grinding roller units rolling along the driving yoke bush. Raw coal falls onto a transmission yoke lining tile distributor from a central coal dropping pipe of the medium-speed vertical coal mill, is conveyed to a grinding roller path under the action of centrifugal force, and is ground through a grinding roller device. The three grinding roller devices are uniformly distributed on the transmission yoke lining tile roller path along the circumferential direction, the downward grinding force is generated by a hydraulic loading system, the grinding force is uniformly applied to the three grinding roller devices through a three-point system statically determined by a pressure frame of the coal mill, and the grinding force is transmitted to a foundation of the coal mill through a bottom plate after passing through an upper pull rod, a lower pull rod, the pressure frame, the grinding roller devices, the transmission yoke lining tile, a transmission yoke, a speed reducer and a loading hydraulic cylinder. The grinding and drying of raw coal are carried out simultaneously, primary air uniformly enters the periphery of the transmission yoke bush through a primary air ring device of the coal mill, and pulverized coal which is cut from the transmission yoke bush and thrown out in a tangential direction is blown to a powder selecting device at the upper part of the coal mill.

The primary air ring device of the medium-speed vertical coal mill comprises an outer ring and an inner ring of the coal mill, wherein the outer ring is fixed in a base shell of the coal mill, and the inner ring is fixed on a transmission yoke of the coal mill. The outer ring is stationary in the coal mill base housing and the inner ring is driven by the coal mill drive yoke to rotate with the drive yoke. The lower parts of the outer ring and the inner ring are primary air chambers of the medium-speed vertical coal mill, and the air flow of the primary air chambers forms high-speed rotating air flow along with the relative rotation of the inner ring and the outer ring, so that an upward rotating acting force is applied to pulverized coal ground rolled on a millstone of the medium-speed vertical coal mill, and the pulverized coal finally enters a hearth for combustion through a powder selecting device. The primary air ring device of the medium-speed vertical coal mill is a key device in a pulverizing device, provides guiding conveying power for pulverized coal after rolling, enables air pressure and air speed to be distributed relatively uniformly due to relative movement of an inner ring and an outer ring, and directly influences the running state of the medium-speed vertical coal mill due to the working state and performance of the medium-speed vertical coal mill.

At present, the structure of a primary air ring device of a domestic medium-speed vertical coal mill is in an integrally cast circular ring shape, a certain gap is formed between the inner diameter of an outer ring and the outer diameter of an inner ring, primary air enters a coal mill through the gap and blades during operation of the medium-speed vertical coal mill and rotates relatively to form high-speed rotating air flow, and pulverized coal thrown from a driving yoke lining plate in a cutting direction is blown to a separator on the upper part of the coal mill. However, the primary air blown out from the inner ring of the primary air ring device of the existing medium-speed vertical coal mill has irregular flow direction and uneven air volume, has adverse effects on the whole combustion process, ash removal process and desulfurization process of a boiler body, a large amount of primary wind energy does useless work, the effective output rate is low, the productivity and the output of the medium-speed vertical coal mill are seriously affected, and the disassembly, assembly and transportation are inconvenient.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems of irregular flow direction of primary air blown out by a primary air ring device of the conventional medium-speed vertical coal mill, uneven air volume and inconvenience in disassembly, assembly and transportation, the utility model provides a primary air ring device of a medium-speed vertical coal mill, which comprises an inner ring and an outer ring; the inner ring and the outer ring are connected in a split manner; the outer ring is fixed in the coal mill base shell, and the inner ring is fixed on a coal mill transmission yoke; the inner ring rotates with rotation of the coal pulverizer drive yoke; a folding seal multi-flow passage is arranged between the inner ring and the outer ring; a first wind blocking ring is arranged at the lower part in the shell of the coal mill base; a second wind resistance ring is arranged at the lower part of the inner ring; the first wind resistance ring and the second wind resistance ring form a folding structure; the first choke ring, the second choke ring and the outer ring form a first chamber; and a third wind resistance ring is arranged at the lower part of the outer ring, and the third wind resistance ring and the outer ring body form a second chamber.

Preferably, the installation gaps of the inner ring and the outer ring are respectively 3-5mm, 4-6mm and 4-8 mm.

Preferably, the third choke ring is installed in a slant installation manner.

Preferably, the second chamber is a folded structure.

The utility model provides a wind ring device once of vertical coal pulverizer of intermediate speed is through rolling over to the sealed multithread way of formula for the inner ring blows out once wind flow direction law controllable, and the amount of wind is even, and wind energy utilization rate is high once, and the effective output rate of the amount of wind is high, provides powerful help to the vertical coal pulverizer productivity of intermediate speed, provide oneself. The utility model provides an inner ring and outer loop of the primary wind ring device of the medium-speed vertical coal mill adopt the split connection mode, and easy dismounting is convenient for highway transportation.

Drawings

FIG. 1 is a schematic structural diagram of a primary air ring device of a medium-speed vertical coal mill in the embodiment;

fig. 2 is a schematic structural diagram of the medium-speed vertical coal mill in the embodiment.

Detailed Description

The technical solution of the present invention will be further described with reference to the accompanying drawings and examples.

Referring to fig. 1 and 2, the primary air ring device of the medium-speed vertical coal mill provided in this embodiment includes an inner ring 1 and an outer ring 2, the inner ring 1 and the outer ring 2 are connected in a split manner, the outer ring 2 is fixed in a coal mill base housing 3, and the inner ring 1 is fixed on a coal mill transmission yoke 6; the inner ring 1 rotates along with the rotation of the coal mill transmission yoke 6; a folding seal multi-flow passage is arranged between the inner ring 1 and the outer ring 2; a first wind resistance ring 8 is arranged at the lower part in the coal mill base shell 3; the lower part of the inner ring 1 is provided with a second wind resistance ring 9; the first wind resistance ring 8 and the second wind resistance ring 9 form a folding structure; the first choke ring 8, the second choke ring 9 and the outer ring 2 form a first chamber 10; the lower part of the outer ring 2 is provided with a third choke ring 11, and the third choke ring 11 and the body of the outer ring 2 form a second chamber 12.

In practical application, the installation gaps of the inner ring 1 and the outer ring 2 in this embodiment should be determined according to the vibration range of the coal mill during operation, for example, 3-5mm, 4-6mm, and 4-8mm respectively (as shown in fig. 1), and the inner ring 1 and the outer ring 2 are rivet welded pieces, and both the inner ring 1 and the outer ring 2 have a hardness of HB400, and have a very high hardness and are very wear-resistant, and the actual service life is longer than or equal to 30000 hours (8000 hours is one year), which can meet the requirements of the existing power plant on the powder manufacturing equipment and an overhaul period of the power plant of 3-5 years. Under the normal use condition, the blade micro-abrasion on the inner ring 1, the interval between the blade and the blade can not be increased, under the condition that the primary air chamber air pressure is unchanged, the output section is changed slightly, the output air volume is reduced, the quality of the output pulverized coal is ensured, the pulverized coal fineness R90 keeps 10% -30% of the original design, the high-quality pulverized coal is input into a boiler for combustion, the boiler burnout point and the boiler tail flue gas temperature are consistent with the original design, and the method brings convenience to the processes of boiler decoking and deslagging, flue gas ash removal, flue gas desulfurization and the like.

In practical application, the first wind resistance ring 8, the second wind resistance ring 9 and the third wind resistance ring 11 are all made of high-strength wear-resistant steel WNM 400; the first wind resistance ring 8 and the second wind resistance ring 9 form a folding structure, and the folding structure has the functions of reducing pressure and resisting dust for primary wind; the first choke ring 8, the second choke ring 9 and the outer ring 2 form a first chamber 10, the first chamber 10 and the primary air chamber 5 have pressure difference, and the first chamber 10 has the functions of reducing pressure and blocking dust for primary air; the third wind resistance ring 11 is installed in an inclined mode, and can play a role in reducing pressure and resisting dust for primary wind; the third choke ring 11 and the outer ring 2 body form a second chamber 12, and the second chamber 12 is of a folding structure; the first chamber 10 and the second chamber 12 form a pressure difference (the air pressure of the first chamber 10 is larger than the air pressure of the second chamber 12), and the second chamber 12 and the coal mill body form a pressure difference (the air pressure of the coal mill body is larger than the air pressure of the second chamber 12), so that an optimal sealing and dust blocking effect is achieved.

In the specific application, the primary air blown upwards from the primary air chamber of the medium-speed vertical coal mill carries discharged dust, and after the dust is reduced and blocked by pressure reduction of a folding-type sealed multi-flow passage, the air pressure and the air speed are reduced, and the air-powder ratio is reduced, for example, the local measured air speed of the flow passage is reduced to 5-20m/s from the original design 90m/s, and the local air-powder ratio of the flow passage is reduced to 0.1kg/kg from the original design 1.5 kg/kg.

The inner ring and the outer ring of the primary air ring device of the medium-speed vertical coal mill in the embodiment adopt a split connection mode, and can be disassembled and assembled from a manhole during replacement, so that the disassembly and assembly are convenient, and the highway transportation is convenient. The primary air ring device of the medium-speed vertical coal mill has the advantages that through the folding sealing multi-flow channel, the abrasion of the outer ring and the inner ring on the base body is reduced, the abrasion of key parts such as a shell of the coal mill, a grinding roller device and a roller frame of the coal mill is reduced, the coal mill keeps efficient operation, and the safety production efficiency is improved. The primary wind flow direction rule that this embodiment intermediate speed vertical coal mill primary wind ring device inner ring blew out is controllable, and the amount of wind is even, and primary wind energy utilization rate is high, and the effective output rate of the amount of wind is high, has formed the inside whirl system rule of intermediate speed vertical coal mill, provides powerful help to intermediate speed vertical coal mill productivity, exerting oneself. The primary air ring device of the medium-speed vertical coal mill can control the fineness of pulverized coal, improves the combustion efficiency of a power plant boiler, and ensures the normal operation of auxiliary equipment.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (4)

1. A primary air ring device of a medium-speed vertical coal mill is characterized by comprising an inner ring and an outer ring; the inner ring and the outer ring are connected in a split manner; the outer ring is fixed in the coal mill base shell, and the inner ring is fixed on a coal mill transmission yoke; the inner ring rotates with rotation of the coal pulverizer drive yoke; a folding seal multi-flow passage is arranged between the inner ring and the outer ring; a first wind blocking ring is arranged at the lower part in the shell of the coal mill base; a second wind resistance ring is arranged at the lower part of the inner ring; the first wind resistance ring and the second wind resistance ring form a folding structure; the first choke ring, the second choke ring and the outer ring form a first chamber; and a third wind resistance ring is arranged at the lower part of the outer ring, and the third wind resistance ring and the outer ring body form a second chamber.

2. A primary air ring device of a medium speed vertical coal mill according to claim 1, wherein the installation gaps of the inner ring and the outer ring are respectively 3-5mm, 4-6mm and 4-8 mm.

3. A primary air ring device for a medium speed vertical coal mill as defined in claim 1 wherein said third choke ring is installed in a tilted manner.

4. A medium speed vertical coal mill primary air ring apparatus according to claim 1, wherein said second chamber is of a folded structure.

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